Mr Sharif, with eight others, was also charged with kidnapping in an incident relating to the day of the coup, 12 October, when Mr Sharif told airport officials in Karachi to refuse landing rights to a plane carrying General Musharraf.
Mr Sharif had been on the verge of installing an ally as the new army chief of staff and had been trying to divert the general's plane away from Pakistan. The aircraft had only 10 more minutes of fuel remaining and was re-routed to the city of Nawabshah. The coup was instigated within hours of this incident. Mr Sharif, who is in military custody, was also accused of assembling people with the purpose of killing and physical endangerment, both of which carry prison terms. Treason carries the death penalty.
The move comes on the eve of the Commonwealth summit tomorrow and prompted US calls for fair treatment of Mr Sharif.
"We have continued to raise our concerns with Pakistani authorities about ... Sharif's well-being and our concern he be accorded due process," a State Department spokesman said.
The decision to charge Mr Sharif is more evidence that General Musharraf intends pursuing his campaign against "the corrupt politicians."